What is it about the Germans? No nation has risen to such sublime heights and sunk to such hideous depths; no nation has been so creative and so destructive; no nation evokes such admiration and alarm in equal measure. When and why did the Germans come by their uniquely problematic destiny? How could the nation of Kant and Goethe also be the nation of Hitler and Himmler?

In The German Genius: Europe's Third Renaissance, the Second Scientific Revolution and the Twentieth Century (Simon and Schuster, £30), the British journalist Peter Watson makes a valiant and voluminous attempt to answer what used to be known as the German Question. The German Genius presents a huge corpus of scholarship in easily digestible form, and its range is astonishing. No professor, least of all a German one, would have dared to essay such a synthesis; so much the worse for the professors.

A German Genius? Daniel Kehlmann, the enfant terrible of German letters

If, after nearly 1,000 pages, Watson ultimately fails to give a satisfactory answer to the German Question, that may be because none exists. It is not merely that no one scholar can ever hope to master all the material necessary to come to a balanced, definitive conclusion. Rather, the very notion of passing judgment on the Germans is incoherent, for the reason given by Edmund Burke in his plea for conciliation with America: "I do not know the method of drawing up an indictment against a whole people."

True, in the German case, the two world wars both evoked demands for just such an indictment. The Versailles Treaty laid the whole burden of responsibility for the Great War on "the aggression of Germany and its allies". The reparations imposed on Germany by the treaty were paid off only last month, almost 90 years later, and just four years after Britain finished paying off wartime loans to the US. That historical curiosity is a reminder that the "war guilt" for which, so it was claimed at the time, the German people was being punished, was a myth. The fact is that wars are expensive, and not only for the losers. After the Second World War, the Nuremberg trials were also seen by some as an indictment of the Germans, but in fact the Western allies consistently distinguished between the Nazi leaders and the German people. Propaganda in occupied Germany based on the concept of collective guilt was briefly tried after the full extent of the Holocaust became clear, but it soon ceased to play any part in Allied policy. Since 1945, a few writers, from A. J. P. Taylor to Daniel Goldhagen, have traced the roots of Nazi ideology throughout German history, but the popular and academic consensus has been overwhelmingly favourable to the Germany that emerged after the war. Even the harshest critics of the Germans' readiness under Hitler to abandon Western civilisation do not doubt the solidity of the post-war German achievement.

For Peter Watson, "That is all in the past...such a betrayal could not take place again." His thesis is that non-Germans in general, and the British in particular, have been unable or unwilling to look "beyond Hitler" and to appreciate the extraordinary ways in which German philosophers, writers, scientists, architects, artists, musicians, theologians and countless other thinkers have altered our "intellectual skyline". He even has an appendix, "Thirty-five Underrated Germans", all of whom contributed crucially to our world, but who are unknown to most of us and even to their compatriots.